Do the 4.0 have knock sensors?

[atistang]

I have noticed my explorer is pinging under loads, the weird part is there are no check engine lights, and being a coil pack set up i don't see how the timing could be to far advanced. the only thing i can think of is the knock sensor isn't working right and not retarding the timing like it should.

Do they even have knock sensors? Anyone else experience this problem?

 

[gsmaclean]

My 94 knocks like crazy anytime under load (i.e. going up hills) unless I put premium in it. Not about to do that, so I just listen to the pinging. The owners manual actually says "some knocking is normal". Never heard that from a manufacturer before!

 

[atistang]

screw that, i don't want to be putting an engine in soon

I was gonna run premium in my next tank and see if it still does it, if it does,'t then i'm gonna try seafoam to get any carbon buildup out of it i can, if that don't work then i'll go from there

 

[MrShorty]

Carbon buildup is one cause. A couple of other possible causes that are common to the 1st gen 4.0 relate to a slight lean condition. Often caused by a dirty MAF or loose lower intake bolts or other vacuum leak. This has been discussed a lot here if you are up to wading through the search function.

 

[jackieman402]

Mine had a dirty MAF filament. I used some contact cleaner to fix it.

 

[atistang]

Carbon buildup is one cause. A couple of other possible causes that are common to the 1st gen 4.0 relate to a slight lean condition. Often caused by a dirty MAF or loose lower intake bolts or other vacuum leak. This has been discussed a lot here if you are up to wading through the search function.

Mine had a dirty MAF filament. I used some contact cleaner to fix it.

have you had any luck with that MAF cleaner? my roommate has a can of it, i guess i will hit it with that



also the intake manifold bolts just loosen up? i guess i'll put a wrench on them and see if they are clean

 

[92exp4x4]

All of my explorers ping some worse than others. I run premium in all mine its only $4 dollars more on a complete fill up if its 20 cents more than regular(it is around here). My 93 is the worst but i think its the 207,000 miles on the engine.

do a search on pinging You will find alot, if you have not already.

By the way proper torque for lower intake bolts are: 15-18 ft. lbs and should be tightened in sequence.
The upper manifold nut torque is: 15-18 ft. lbs

You will have to remove the upper intake to access the lower intake's bolts

good luck

 

[jackieman402]

I used a Q-Tip and a can of regular electronic contact cleaner from work, and it worked fine. My MAF had a sooty-looking substance on the filament. Make sure to unplug the Maf from the wiring harness when you do this.

There are other things which can cause your knocking (like the loose intake bolts), but the MAF is easy to check.